High capacity draft gear with friction and a plurality of spring cushioning elements



4 Sheets-Sheet 1 IN V EN TOR.

1957 D. s. CAMPBELL HIGH CAPACITY DRAFT GEAR WITH FRICTION AND A PLURALITY 0F SPRING CUSHIONING ELEMENTS Filed Oct. 28, 1953 Oct. 22, 1957 D. s. CAMPBELL 2,8

HIGH CAPACITY DRAFT GEAR WITH FRICTION AND A PLURALITY OF SPRING CUSHIONING ELEEENTS Filed Oct. 28. 1953 4 Sheets-Sheet 2 a? l a w i; 5 Qgi INVENTOR. fiMZY/d W M, 29mm MW Oct. 22, 1957 D. s. CAMPBELL HIGH CAPACITY DRAFT GEAR WITH FRICTION AND A PLURALITY OF SPRING CUSHIONING ELEMENTS 4 Sheets-Sheet 3 Filed 001;. 28. 1953 iwww W INVENTOR.

. A m w 06L 1957 D. s. CAMPBELL 2,810,484

HIGH CAPACITY DRAFT GEAR WITH FRICTION AND A PLURALITY 0F SPRING CUSHIONING ELEMENTS Filed Oct. 28. 1953 4 Sheets-Sheet 4 United States Patent HIGH CAPACITY DRAFT GEAR WITH FRICTION AND A PLURALITY 0F SPRING CUSHIONING ELEMENTS David S. Campbell, Glen Ellyn, Ill., assignor to Cardwell Westinghouse Company, a corporation of Delaware Application October 28, 1953, Serial No. 388,789

4 Claims. (Cl. 21333) This invention relates to draft gears for railroad cars, and has for its principal object to provide a gear of high capacity in which the energy absorption increases as the gear closes and the recoil on release is controlled by energy absorption.

Generally speaking, this is accomplished by combining a friction mechanism and a spring cushioning element in tandem, the latter including-a plurality of groups, one of which acts in advance of another.

Further objects and advantages of the invention will be apparent as the description is read in connection with the accompanying drawings, in which:

Fig. 1 is a horizontal section through familiar parts of a freight car showing the draft gear applied;

Fig. 2 is a vertical section of the same;

Fig. 3 is an enlarged horizontal section through the draft gear and portions of the draft rigging showing the gear in full release;

Fig. 4 is a similar view showing the draft gear compressed in buff;

Fig. 5 is a vertical section through the draft gear and the front follower with the draft gear in full release;

Fig. 6 is a front elevation of the draft gear;

Figs..7, 8, and 9 are vertical cross sections on the lines 7--7, 88, and. 99, respectively, of Fig. 5;

Fig. 10 is a perspective view of the draft gear housing;

Fig. 11 is a-perspective view of groups of intercalated friction plates andfriction shoes forming a part of the friction cushioning element;

Fig. l2 is a perspective View of the plunger forming a part of the same cushioning element; and

Fig. 13 is a perspective view of a wedge follower or spring seat functioning as a part of both cushioning elements.

But these drawings and the corresponding description are for the purpose of illustrative disclosure only, and are not intended to impose unnecessary limitations on the claims.

In Figs. 1 and 2, the draft gear, indicated generally by 10, is shown in the familiar surroundings of center sills 11, draft gear lugs 12, draft yoke 13, coupler butt or shank 14, draft key 15, coupler carrier iron 16, draft gear carrier iron 17, coupler horn 18, and striking plate 19 (all corresponding to Fig. 10.51 of Car Builders Cyclopedia, 1946, p. 944). These parts are so familiar that no specific description is deemed necessary.

The draft gear housing, generally indicated 20 (Figs. 2-10), includes a rear chamber 21 for a cushioning element here shown of the rubber spring type and a front chamber 22 for a friction mechanism in open communication with the rear chamber and open at the front.

A rubber cushioning element, generally indicated by 23, in the chamber 21 includes rubber spring units 24 and spacers 25. In this instance, the element is in three parts or columns, generally indicated A, B, and C.

There is a follower 26 at the front of each column A and C and a combined follower and spring seat 27 at the front of the column B. Ribs 28 (Fig. 9) lengthwise ice 2. to the housing 20 in connection with the side walls keep the units of the columns in-line.

The friction mechanism includes a plunger 30 having wedge surfaces 31 'at opposite sidesrcooperating with friction shoes 32, which also cooperatewith wedge surfaces 33 on the follower 27, the group' of four parts in thrust relation to the intermediate rubber spring column B.

The combined follower and spring. seat 27 functions as a part of both the rubber cushioning element; and the friction mechanism. It, of course, could be made in' a plurality of pieces, separating the follower function-from the wedge andsspringgseat functions;

The plunger and the wedge follower have opposed spring seats 34 and 35 for a specialrelease spring 36.

Associated with and acted upon by the friction shoes 32 are groups of intercalated plates 5, '6, 7, 8, and 9,.one group at each side of the friction cushioning element.

The plates 6 and 8 are movable with respect to their associates and the casing, and serve as thrust members between the front follower 37 and the followers 26 for the rubber spring columns A-and C.

The plates 5, 7, and 9 are stationary,and so held within the casing by verticalribs 38 and 39' (Figs. 3 and 4) and horizontal ribs 40 and-40a (Fig. 10).

7 Assembly For convenience in assembly, the housing 20 is provided with openings 50 and 51, and the followers 26 and 27 are providedwith openings 52 and 53."

After the spring partsA, B,.and C and'the'followers have been inserted and brought into position, the springs maybe compressed and assembly pins inserted through the openings 50 and 53 tohold them temporarily.

With those spring parts A, B, and C held compressed, the stationary plates 5, 7, and 9-are inserted, followed by the shoes 32, the spring 36,.and the plunger 30, the latter being first turned toward the horizontal position-to bring the arms 42 behind the flanges 41. Finally, the movable friction plates 6 and 7 are inserted, and then'the springs A, B, and C are compressed'a little more and the assembly pins removed andthe springs released. r

Alternatively, the rear wall of the housing may be made separate from. thebody portion, and assemblycan then be accomplished without any preliminary compression.

The capacity of the gear may be varied by varying the angles of the wedge surfaces 31 and 32.

The surfaces 33 are best inclined on the angle of repose of the metal to promote movement.

Generally speaking, the ordinary draft gear for freight cars has a capacity on the order of 21,000 foot pounds with a nominal travel of 2%", which will handle a 50-ton car at approximately four miles an hour. According to this invention, a draft gear may have a capacity on the order of 40,000 foot pounds in 2 /2 travel; and, by increasing the total travel to 3% the loading on the rubber elements may add capacity on the order of 25,000 pounds in the last A of travel beyond the stated 2 /2" of travel mentioned.

Operation In operation, the thrust member 30, acting upon the friction shoes 32 and through them on the follower 27, puts pressure on the intercalated plates, and also on the middle column B of rubber spring unit. Additionally, the thrust member 30, acting against the wedge shoes 32, and they in turn against the follower wedge 27, puts the thrust directly on the column B. Thus, there is cushioning friction and cushioning spring action in tandem to absorb the bufiing shocks. Preferably, this action of the friction mechanism and the middle column B of the spring element performs all the shock absorbing within a selected limit of travelfor example, /2--which alfords very suitable cushioning for what may be termed light bufling shocks.

When the travel goes beyond the selected short limit in the example, /2, the follower 37 comes against the movable plates 6 and 8, forcing them against the followers 26, introducing additional friction and also the cushioning of the columns A and C, thereby adding shock absorption or energy absorption at a high rate. The action continues through the range of the gear until the follower 37 strikes the front end of the draft gear housing 20, which should rarely happen on account of the high capacity available-on the order of 40,000 pounds with 2 /2 of travel and 25,000 additional foot pounds before the gear is compressed.

Upon release of a buffing shock, the spring parts A, B, and C urge the followers and the parts of the friction gear toward release, and the natural rebound'of those elements is controlled and the energy absorbed by the friction. The spring 36 constantly urges the plunger toward release.

In order to temporarily shorten the gear for insertion into the draft gear pocket between the lugs 12, the plunger 33 is provided with oppositely directed arms 42 and 43 to engage the inside ribs 40 near the front of the housing 20, and the arms 42 and 43 are provided with slight projections 44, which require an initial overall compression sufiicient to admit the gear between the lugs 12. After a few normal operations of the gear, the projections 44 will cut into the ribs, and the full release of the gear between the lugs 12 will be permitted.

I claim:

1. In a draft gear for railway cars, a housing having an open end and a closed end, a follower in thrust relation to said open end of said housing, a group of intercalated stationary and movable friction plates within the housing at each side thereof, the movable plates of said groups projecting beyond the open end of said housing to engage said follower during at least a portion of the closure travel of said gear, a plunger seated against said follower and including a thrust wedge, a second wedge longitudinally spaced from the first-mentioned wedge, laterally spaced wedge shoe's between and acted upon by said wedges to engage and press the plates of each of said groups together, said second wedge including a follower portion seating against a central cushioning means of a plurality of independent parallel extending cushioning means disposed in said housing at the closed end thereof, and independent auxiliary followers between each group and a selected portion of the remainder of said cushioning means, such that inward movement of the movable plates during closure of the gear is resisted directly by the said selected portions of the remainder of said cushioning means to provide increased capacity.

2. In a draft gear for railway cars, a housing including a rear chamber and a front chamber in open communication with the rear chamber and open at the front, a plurality of independent parallel extending cushioning means within the rear chamber and including a central cushioning means, a follower for the central cushioning means and independent auxiliary followers for selected portions of the remainder of said plurality of cushioning means, a friction mechanism in said front chamber including a wedge on the front of said first-mentioned follower, a thrust wedge longitudinally spaced from the first-mentioned wedge, laterally spaced wedge shoes between and acted upon by said wedges to urge said shoes laterally, and a group of intercalated stationary and movable friction plates in said housing on opposite sides of said shoes for receiving lateral pressures therefrom, each group extending inwardly into thrust engagement with its auxiliary follower means and extending through the open front of said housing, and a front follower bearing against the outer end of the thrust wedge and having laterally extending portions in overlapping relation with said movable plates to engage therewith during at least a portion of the closure stroke of said gear, the arrangement being such that said selected portions of said cushioning means directly resist inward movement of said movable plates during closure of the gear to substantially increase the capacity.

3. The invention of claim 1 wherein each group of plates includes a plurality of movable friction plates intercalated with a plurality of stationary friction plates.

4. The invention of claim 2 wherein each group of plates includes a plurality of movable friction plates intercalated with a plurality of stationary friction plates.

References Cited in the file of this patent UNITED STATES PATENTS 1 1,650,381 OConnor Nov. 22, 1927 1,831,084 Tucker Nov. 10, 1931 1,938,881 Wildin Dec. 12, 1933 2,197,030 Clark Apr. 16, 1940 

